Bernstein-Durrmeyer-Bezier算子在L_P[0,1]上的逼近性质

对[0,1]上的L—可积函数ф及α>0定义下列B—D—B算子;本文研究了M_(na)(ф,x)当α>0时,在L_P(0,1](1≤p<+∞)的一致逼近;当α≥1时在L_P[O,1]及L~1_P[0,1]逼近度的量化估计。作者在文[4]中定义了B—D—B算子:其中f_(nk)(X)称为Bézeief基函数文[4]研究的是B—D—B称子在C[0,1]空间中的逼近性质,本文继续[4]的工作,专研究这个算子在L_P[0,1](1≤P<+∞)的逼近性质,证明了M_(na)(ф X)当α>0时在L_P[0,1]中为一致逼近,并得到了当α≥1时在L_P[0,1]及L~1_P[0,1]中逼近度的量化估计。     

向量值测度产生的集值测度及性质

由有界变差向量值测度的值域,通过取凸包和闭包,构造了L[0,1],L2[0,1]和C[0,1]空间上的有界变差紧凸集值测度,结果由欧氏空间推广到函数空间.     

INTEGRAL REPRESENTATION OF NONLINEAR OPERATORS

A continuous linear functional on some function space can be represented by an integral which in its usual form is linear. In this paper, we give an integral representation of a nonlinear operator on the space C=C([0,1],X) of continuous functions on [0,1] with values in a Banach space X. This is done by means of a nonlinear integral using a kernel type function.     

一类四阶奇异半正Sturm-Liouville边值问题的正解

在Sturm-Liouville边界条件下研究较广泛的一类四阶奇异半正微分方程,得到其C2[0,1]正解与C3[0,1]正解存在的新结果,并给出了其正解与该边值问题的格林函数之间的某些联系.     

具有Strum—Liouville边界条件的四阶奇异超线性微分方程正解的存在性和不存在性

本文给出Strum-Liouville边界条件下的一类四阶奇异超线性微分方程其C2[0,1]正解存在的充分必要条件和C3[0,1]正解存在的充分条件和必要条件.结果可用于判断给定的边值问题其正解的存在性与不存在性.     

四阶奇异微分方程边值问题正解的存在性

利用上下解方法给出了一类四阶微分方程奇异边值问题有C2[0,1]和C3[0,1]正解的充分条件.     

四阶奇异边值问题两个正解的存在性

利用e-范数和锥上的不动点定理,给出了四阶微分方程奇异边值问题两个C2[0,1]和C3[0,1]正解的存在性.     

四阶奇异边值问题两个正解的存在性

本文利用锥压缩和锥拉伸不动点定理,给出了四阶微分方程奇异边值问题两 个C2[0,1]和C3[0,1]正解的存在性.     

一类非紧度量空间上的连续函数空间（英文）

对一个度量空间（X,ρ）,设↓C（X）是从X到I=[0,1]的连续函数下方图形全体之集赋予由度量空间X×I上的Hausdorff度量诱导出的拓扑.本文证明了下面的结果:如果（X,ρ）是一个非紧的、局部紧的、可分的、完全有界的度量空间,则↓C（X）同胚于c₀当且仅当X上的孤立点全体之集在X中不稠密,这里c₀={（xn）n∈N∈[-1,1]ω:sup|x+n|<1且lim_n→+∞x_n=0}.特别地,对赋予通常度量的开区间（0,1）,↓C（（0,1））同胚于c₀.     

超线性奇异边值问题正解存在的充分必要条件

本文利用锥上的不动点定理给出了四阶超线性微分方程奇异边值问题C2[0,1]和C3[0,1]正解存在的充分必要条件.     

The Structure of Lattice-Subspaces

In Polyrakis (1983; Math. Proc. Cambridge Phil. Soc. 94, 519) it is proved that each infinite-dimensional, closed lattice-subspace of . . .₁ is order-isomorphic to . . .₁ and in Polyrakis (1987; Math. Anal. Appl. 184, 1) that each separable Banach lattice is order isomorphic to a closed lattice-subspace of C[0,1]. Therefore . . .₁ contains only one lattice-subspace but C[0,1] contains all the separable Banach lattices. In the first section of this article we study the kind of the order embeddability of a separable Banach lattice in C[0,1]. We show that the AM spaces have the ``best' behavior and the AL-spaces the ``worst'. In the second section we prove that the closure of a lattice-subspace is not necessarily a lattice-subspace and in the least one we study lattice-subspaces with positive bases.     

Two-Sided Estimates of the $$K$$ -Functional for Spaces of Functions of Generalized Bounded Variation

Functional Analysis and Its Applications - A two-sided estimate is proposed for the $$K$$ -functional of the pair $$(C[0,1], BV(X))$$ , where $$BV(X)$$ is the space of functions of generalized...     

Complete spaces and zero-one measures

It is the purpose of this paper to characterize the complete spaces in the sense of [6] by measure-theoretic properties. Let (X,) be a measurable space and let be a subpaving of satisfying certain closure properties, then X is-complete iff every 0,1-valued-regular measure on is a Dirac measure. In particular, we obtain Hewitt's well-known theorem that a completely regular space X is realcompact iff every 0,1-valued Baire measure on X is a Dirac measure. The main tool for our investigations is an extension theorem for measures due to Topsoe [10].     

Sierpinski Gasket上布朗运动的维数性质

本文研究Sierpinski Gasket上的布朗运动X的象集、图集的Hausdorff维数性质,证明了存在零概率集Ⅳ,若ω∈Nc,则对任意紧集F(?)[0,∞),有(i)dimX(F+t)=min(α-1dimF,df),a.e.t>0,(ii)dimGrX|F+t=min(α-1dimF,(1-α)df+dimF),a.e.t>0,其中ds=log3/log2,α=log2/log5.     

Lineability of sets of nowhere analytic functions

Although the set of nowhere analytic functions on [0,1] is clearly not a linear space, we show that the family of such functions in the space of C^∞-smooth functions contains, except for zero, a dense linear submanifold. The result is even obtained for the smaller class of functions having Pringsheim singularities everywhere. Moreover, in spite of the fact that the space of differentiable functions on [0,1] contains no closed infinite-dimensional manifold in C([0,1]), we prove that the space of real C^∞-smooth functions on (0,1) does contain such a manifold in C((0,1)).     

The hyperspace of the regions below of all lattice-value continuous maps and its Hilbert cube compactification

Let L be a continuous semilattice. We use USC(X, L) to denote the family of all lower closed sets including X × {0} in the product space X × AL and ↓1 C(X,L) the one of the regions below of all continuous maps from X to AL. USC(X, L) with the Vietoris topology is a topological space and ↓C(X, L) is its subspace. It will be proved that, if X is an infinite locally connected compactum and AL is an AR, then USC(X, L) is homeomorphic to [-1,1]ω. Furthermore, if L is the product of countably many intervals, then ↓ C(X, L) is homotopy dense in USC(X,L), that is, there exists a homotopy h : USC(X,L) × [0,1] →USC(X,L) such that h0 = idUSC(X,L) and ht(USC(X,L)) C↓C(X,L) for any t > 0. But ↓C(X, L) is not completely metrizable.     

Analytic Semigroups on C [0,1] Generated by Some Classes of Second Order Differential Operators

C [0,1], α > 0 in (0,1) and α(1), we consider the second order differential operator on C[0,1] defined by Au: = αu″ + βu′, where D(A) may include Wentzell boundary conditions. Under integrability conditions involving √α and β/√α, we prove the analyticity of the semigroup generated by (A,D(A)) on Co[0,1], Cπ[0,1] and on C[0,1], where Co[0,1]: {u∈ C[0,1]|u (1)} and Cπ[0,1]: = {u∈ C[0,1]| u (0) = u (1)}. We also prove different characterizations of D(A) related to some results in [1], where β≡ 0, exhibiting peculiarities of Wentzell boundary conditions. Applications can be derived for the case αx = x ^k (1 - x )^kγ(x )(k≥j/2, x∈ [0,1], γ∈ C{0,1}).